Python学习 代码 四

>>> bob2={'name':{'first':'Bob','last':'Smith'},
'age':42,
'job':['software','writing'],
'pay':(40000,50000)}
>>> bob2
{'job': ['software', 'writing'], 'name': {'last': 'Smith', 'first': 'Bob'}, 'age': 42, 'pay': (40000, 50000)}
>>> bob2['name']
{'last': 'Smith', 'first': 'Bob'}
>>> bob2['name']['last']
'Smith'
>>> bob2['pay'][1]
50000
>>> for job in bob2['job']:
print(job)

software
writing
>>> bob2['job'][-1]
'writing'
>>> bob2['job'].append('janitor')
>>> bob2
{'job': ['software', 'writing', 'janitor'], 'name': {'last': 'Smith', 'first': 'Bob'}, 'age': 42, 'pay': (40000, 50000)}
>>>
>>>
>>>
>>>
>>>
>>> bob=dict(name='Bob Smith',age=42,pay=30000,job='dev')
>>> sue=dict(name='Sue Jones',age=45,pay=40000,job='hdw')
>>> bob
{'job': 'dev', 'pay': 30000, 'age': 42, 'name': 'Bob Smith'}
>>> db={}
>>> db['bob']=bob
>>> db['sue']=sue
>>>
>>> db['bob']['name']
'Bob Smith'
>>> db['sue']['pay']
40000
>>> db['sue']['pay']=50000
>>> db['sue']['pay']
50000
>>> db
{'sue': {'job': 'hdw', 'pay': 50000, 'age': 45, 'name': 'Sue Jones'}, 'bob': {'job': 'dev', 'pay': 30000, 'age': 42, 'name': 'Bob Smith'}}
>>> import pprint
>>> pprint.pprint(db)
{'bob': {'age': 42, 'job': 'dev', 'name': 'Bob Smith', 'pay': 30000},
'sue': {'age': 45, 'job': 'hdw', 'name': 'Sue Jones', 'pay': 50000}}
>>> for key in db:
print(key,'=>',db[key]['pay'])

sue => 50000
bob => 30000
>>>
>>> for key in db:
print(db[key]['name'].split()[-1])
db[key]['pay']*=1.10

Jones
Smith
>>> for record in db.values():print(record['pay'])

55000.00000000001
33000.0
>>> x=[db[key]['name'] for key in db]
>>> x
['Sue Jones', 'Bob Smith']
>>> x=[rec['name'] for rec in db.values()]
>>> x
['Sue Jones', 'Bob Smith']
>>> db['tom']=dict(name='Tom',age=50,pay=0,job=None)
>>> db['tom']
{'job': None, 'pay': 0, 'age': 50, 'name': 'Tom'}
>>> db['tom']['name']
'Tom'
>>> list(db.keys())
['tom', 'sue', 'bob']
>>> len(db)
3
>>> [rec['age'] for rec in db.values()]
[50, 45, 42]
>>> [rec['name'] for rec in db.values() if rec['age']>=45]
['Tom', 'Sue Jones']
>>>